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FILESYSTEMS(5) Linux Programmer's Manual FILESYSTEMS(5)

NAME
filesystems - Linux filesystem types: ext, ext2, ext3, ext4, hpfs, iso9660, JFS, minix,
msdos, ncpfs nfs, ntfs, proc, Reiserfs, smb, sysv, umsdos, vfat, XFS, xiafs

DESCRIPTION
When, as is customary, the proc filesystem is mounted on /proc, you can find in the file
/proc/filesystems which filesystems your kernel currently supports; see proc(5) for more
details. There is also a legacy sysfs(2) system call (whose availability is controlled by
the CONFIG_SYSFS_SYSCALL kernel build configuration option since Linux 3.15) that enables
enumeration of the currently available filesystem types regardless of /proc availability
and/or sanity.

If you need a currently unsupported filesystem, insert the corresponding kernel module or
recompile the kernel.

In order to use a filesystem, you have to mount it; see mount(2) and mount(8).

The following list provides a short description of the available or historically available
filesystems in the Linux kernel. See the kernel documentation for a comprehensive
description of all options and limitations.

ext is an elaborate extension of the minix filesystem. It has been completely
superseded by the second version of the extended filesystem (ext2) and has been
removed from the kernel (in 2.1.21).

ext2 is the high performance disk filesystem used by Linux for fixed disks as well as
removable media. The second extended filesystem was designed as an extension of
the extended filesystem (ext). See ext2(5).

ext3 is a journaling version of the ext2 filesystem. It is easy to switch back and
forth between ext2 and ext3. See ext3(5).

ext4 is a set of upgrades to ext3 including substantial performance and reliability
enhancements, plus large increases in volume, file, and directory size limits. See
ext4(5).

hpfs is the High Performance Filesystem, used in OS/2. This filesystem is read-only
under Linux due to the lack of available documentation.

iso9660 is a CD-ROM filesystem type conforming to the ISO 9660 standard.

High Sierra
Linux supports High Sierra, the precursor to the ISO 9660 standard for CD-
ROM filesystems. It is automatically recognized within the iso9660
filesystem support under Linux.

Rock Ridge
Linux also supports the System Use Sharing Protocol records specified by the
Rock Ridge Interchange Protocol. They are used to further describe the
files in the iso9660 filesystem to a UNIX host, and provide information such
as long filenames, UID/GID, POSIX permissions, and devices. It is
automatically recognized within the iso9660 filesystem support under Linux.

JFS is a journaling filesystem, developed by IBM, that was integrated into Linux in
kernel 2.4.24.

minix is the filesystem used in the Minix operating system, the first to run under Linux.
It has a number of shortcomings, including a 64 MB partition size limit, short
filenames, and a single timestamp. It remains useful for floppies and RAM disks.

msdos is the filesystem used by DOS, Windows, and some OS/2 computers. msdos filenames
can be no longer than 8 characters, followed by an optional period and 3 character
extension.

ncpfs is a network filesystem that supports the NCP protocol, used by Novell NetWare. It
was was removed from the kernel in 4.17.

To use ncpfs, you need special programs, which can be found at ⟨ftp://ftp.gwdg.de
/pub/linux/misc/ncpfs⟩.

nfs is the network filesystem used to access disks located on remote computers.

ntfs is the filesystem native to Microsoft Windows NT, supporting features like ACLs,
journaling, encryption, and so on.

proc is a pseudo filesystem which is used as an interface to kernel data structures
rather than reading and interpreting /dev/kmem. In particular, its files do not
take disk space. See proc(5).

Reiserfs is a journaling filesystem, designed by Hans Reiser, that was integrated into Linux
in kernel 2.4.1.

smb is a network filesystem that supports the SMB protocol, used by Windows for Work‐
groups, Windows NT, and Lan Manager. See ⟨https://www.samba.org/samba/smbfs/⟩.

sysv is an implementation of the System V/Coherent filesystem for Linux. It implements
all of Xenix FS, System V/386 FS, and Coherent FS.

umsdos is an extended DOS filesystem used by Linux. It adds capability for long file‐
names, UID/GID, POSIX permissions, and special files (devices, named pipes, etc.)
under the DOS filesystem, without sacrificing compatibility with DOS.

tmpfs is a filesystem whose contents reside in virtual memory. Since the files on such
filesystems typically reside in RAM, file access is extremely fast. See tmpfs(5).

vfat is an extended FAT filesystem used by Microsoft Windows95 and Windows NT. vfat
adds the capability to use long filenames under the MSDOS filesystem.

XFS is a journaling filesystem, developed by SGI, that was integrated into Linux in
kernel 2.4.20.

xiafs was designed and implemented to be a stable, safe filesystem by extending the Minix
filesystem code. It provides the basic most requested features without undue com‐
plexity. The xiafs filesystem is no longer actively developed or maintained. It
was removed from the kernel in 2.1.21.

SEE ALSO
fuse(4), btrfs(5), ext2(5), ext3(5), ext4(5), nfs(5), proc(5), sysfs(5), tmpfs(5), xfs(5),
fsck(8), mkfs(8), mount(8)

COLOPHON
This page is part of release 5.10 of the Linux man-pages project. A description of the
project, information about reporting bugs, and the latest version of this page, can be found
at https://www.kernel.org/doc/man-pages/.

Linux 2020-12-21 FILESYSTEMS(5)